A buffer circuit is designed to respond to a predetermined range of input voltages and produce an output voltage that falls within a predetermined range. CMOS buffer circuits are mainly used for driving devices connected to an output stage, particularly devices having capacitance. If a signal bus in a memory has to drive a large load, or a clock signal has to drive a large load within a chip in a circuit only formed of logic devices, buffer circuits are needed for the bus signal and the clock signal.